I have a situation with too much flow/ not enough flow. I built a sump with a 1" pvc style overflow. I have a 1500 gph return submersible pump. When I first hooked up this sump, the pump was pulling faster than what the overflow could do. So I bought a ball valve to put on the return line to try and tweak the pump to keep up with the overflow. Now that I have turned everything on my sump ether fills up to much or not enough. I spent 5 hours last night trying to get this right. I finally thought I hit the jackpot until this morning when the sump was bled all the way down and the pump was pulling air and water. So I tried tweaking it again. No success! Can anyone please advise me on what I could do. Last night I've never seen my Coral more happy than when he had the flow of the water swooshing by. Patrick
can you post a design idea of your overflow and the exact pump you are using? a general overflow should only drain what is being supplied above the normal tank volume by the pump. i would also consider using a larger diameter overflow then the return line to make sure you can overcompensate for the flow. i personally would use 1 1/4 drain for a 3/4 return or something along those lines to be safe. depending on pump and head pressure i dont think the one inch line will return enough to keep up with the pump.
I agree, the overflow should be larger than the returns. I use 1/12" overflows to 1" return and then down to 3/4" locline. This allows me to adjust the flow according to the output of the pump. It's always good to have the overflows capable of handeling the max flow of the return pump.
i think its the diameter killing you. up it to 1 1/2 or 1 1/2 and you should be ok. also another design may help. i have used this one successfully in the past. http://www.saltwaterfish.com/vb/showthread.php?t=288154 and here is a gph estimator for pvc overflows 3/4" = 330 gph 1" = 600 gph 1 1/4" = 910 gph 1 1/2" = 1,300 gph 1 3/4" = 1,800 gph 2" = 2,350 gph 2 1/4" = 2,960 gph 2 1/2" = 3,650 gph 2 3/4 = 4,450 gph 3" = 5,280 gph
So what do you do? Do you use 2 overflows and 1 return? By that thread it looks like you use 2 overflows.
i only used one. that was the first pic i could find of that particular design. go 1 1/2 to be safe and you should be fine. also this method will auto start its own siphon in case of power outage so you dont have issues to worry about.
This design really makes a lot of common since. It's funny how the most simple to make ideas really work the best. I'm off to the Home Depot. I will let you know how it turns out. ThankYou for all the help. Patrick
